Analyses of non-aqueous reactive polymer insulation layer in high geothermal tunnel

The scenario of geothermal tunnel is commonly observed around the world,and increases with the new constructions in the long and deep tunnels,for example in China.Tunnel insulation is generally divided into active and passive insulation.In passive insulation,it is an effective way to set low thermal con-ductivity materials as the thermal insulation layer as the choice of insulation material mainly depends on the thermal conductivity.Polymer is a kind of material with good geothermal performance,but there are relatively few studies.In this context,the transient plane source(TPS)method was used to measure the thermal conductivity of the developed polymer.Then,the temperature field of the high geothermal tunnel insulated by the non-aqueous reactive polymer layer was simulated.With the parametric analysis results,the suggestions for the tunnel layers were proposed accordingly.It revealed that the thermal conductivity of polymer first increases and then decreases with temperature.There are two rising sec-tions(?40e10?C and 20e90?C),one flat section(10e20?C)and one descending section(>90?C).It is observed the thermal conductivity of polymer increases with increase of the density of insulation layer and the density,and the thermal conductivity decreases when exposed to high temperatures.The temperature of the surrounding rocks increases with increase of the thermal conductivity and the thickness of polymer.Finally,a more economical thickness(5 cm)was proposed.Based on the parametric study,a thermal insulation layer with thermal conductivity less than 0.045 W/(m K),thickness of 5 cm and a density less than 0.12 g/cm 3 is suggested for practice.

Thermal Emulsion Polymerization without any Conventional Initiators and Emulsifiers

Stable poly（styrene-co-sodium styrene sulfonate） （P（St-NaSS） nanoparticles with broader size distribution were synthesized by thermal emulsion polymerization without any conventional initiators and emulsifiers. The obtained polymer nanoparticles have higher potential, and the particle sizes have broad distribution. The stability of polymer particles originated from the addition of small amounts of ionic comonomer, NaSS, which can act as an emulsifier in somewhat. The monomer conversion could reach up to about 28 wt% in 48 h, and did not increase by further polymerization when higher polymerization temperature （120℃） was employed. This polymerization system may be give some further understand for mechanism of emulsion polymerization.

Non-Thermal Radio Frequency Stimulation of Tubulin Polymerization in Vitro: A Potential Therapy for Cancer Treatment

The use of radio frequency energy is an established technology for certain oncology therapies. Direct inputs of radio frequency (RF) energy as thermal energy are applied to ablate tumors or catalyze secondary reactions in adjunct treatments against certain tumor types. Yet, other applications are being developed which take advantage of properties of RFs that impinge on biological proteins and cells without thermal effects. Here we report a proof-of-concept application of specific, digitally encoded, low power (non-thermal) radio frequency energy in an in vitro preparation of a tubulin polymerization assay. The radio frequency energy signal, designated M2(3), was applied to the tubulin polymerization assay samples during spectrophotometric measurements to assess the effectiveness for enhancing tubulin polymerization. A commercially available taxane (paclitaxel) that promotes tubulin polymerization was used as a control to assess the effectiveness of the M2(3) radio frequency energy signal on tubulin polymerization rates. A low power, specific, digital radio frequency energy signal is capable of promoting tubulin polymerization as effectively as a commercially available taxane.

Nano-Li3V2（PO4）3/C Synthesized by Thermal Polymerization Method as Cathode Material for Lithium Ion Batteries

nano-Li 3 V 2(PO4)3/C 粉末被一个热聚合方法成功地准备。中间的产品粉末和最后的产品李 3 V 2(PO4)3 都是不到 200 nm。碳在李 3 V 2(PO4)3 粒子和剩余的与 4.6wt% 的一个全部的碳内容在粒子之间存在。这 nano-Li 3 没有在电压在 0.1 C 在 100 个周期以后褪色的能力， V 2(PO4)3/C 样品显示出 124 mAh/g 的一个分泌物能力 3.0-4.3 V 响了。优秀的率性能也在 10 C 在 3.0-4.3 V 和 100 mAh/g 在 20 C 与 80 mAh/g 的一个能力被完成在 3.0-4.8 V。这研究建议热聚合方法是合适的综合 nano-Li 3 V 2(PO4)3/C 材料。

Breaking Through Bottlenecks for Thermally Conductive Polymer Composites:A Perspective for Intrinsic Thermal Conductivity,Interfacial Thermal Resistance and Theoretics

Rapid development of energy,electrical and electronic technologies has put forward higher requirements for the thermal conductivities of polymers and their composites.However,the thermal conductivity coefficient(λ)values of prepared thermally conductive polymer composites are still difficult to achieve expectations,which has become the bottleneck in the fields of thermally conductive polymer composites.Aimed at that,based on the accumulation of the previous research works by related researchers and our research group,this paper proposes three possible directions for breaking through the bottlenecks:(1)preparing and synthesizing intrinsically thermally conductive polymers,(2)reducing the interfacial thermal resistance in thermally conductive polymer composites,and(3)establishing suitable thermal conduction models and studying inner thermal conduction mechanism to guide experimental optimization.Also,the future development trends of the three above-mentioned directions are foreseen,hoping to provide certain basis and guidance for the preparation,researches and development of thermally conductive polymers and their composites.

Thermal conductivity model of filled polymer composites

Theoretical and empirical models for predicting the thermal conductivity of polymer composites were summarized since the 1920s.The effects of particle shape,filler amount,dispersion state of fillers,and interfacial thermal barrier on the thermal conductivity of filled polymer composites were investigated,and the agreement of experimental data with theoretical models in literatures was discussed.Silica with high thermal conductivity was chosen to mix with polyvinyl-acetate （EVA） copolymer to prepare SiO2/EVA co-films.Experimental data of the co-films＇ thermal conductivity were compared with some classical theoretical and empirical models.The results show that Agari＇s model,the mixed model,and the percolation model can predict well the thermal conductivity of SiO2/EVA co-films.

Relationship between polymerization degree and cementitious activity of iron ore tailings

The aim of this study is to understand the relationship between the polymerization degree and cememitious activity of iron ore tailings. In light of the poor usage of iron ore tailings, stockpile samples from Tangshan were studied in terms of their ability to become cementitious materials. Compound thermal activation was used to improve the cementitious properties of the tailings, while analyzing methods, such as X-ray diffraction （XRD）, infrared spectroscopy （IR）, nuclear magnetic resonance （NMR）, and X-ray photoelectron spectrometer （XPS）, were employed to study the changes in phase and structure under different activation conditions. The results reveal clear relationships between the binding energies of Si2p and O 1 s, polymerization degree, and cementitious activity of iron ore tailings.

Hydrothermal Synthesis and Crystal Structure of a New Three-dimensional Heterometallic Coordination Polymer

A new 3d-4fheterometallic polymer {[Sm2Cu（PDC）2（SO4）2（H20）6]·2H2O}n 1 has been synthesized by Sm2O3, Cu（SO4）2·5H2O and pyridine-3,5-dicarboxylic acid under hydrothermal conditions. The compound crystallizes in triclinic system, space group Pi, with a = 6.352（7）, b = 10.040（10）, c = 10.315（11） A, α = 94.958（14）, β = 95.556（7）, γ = 99.747（14）°, V = 641.7（12）A3, Z = 1, M, = 1030.63, Dc= 2.651 Mg/m3,μ = 5.615 mm-1, F（000） = 491, the final R = 0.0491 and wR = 0.1345 for 2098 observed reflections with I 〉 2σ（I）. The compound is a three-dimensional network structure in which infinite lanthanide-carboxylate chains are linked by [Cu（$04）2]2- metalloligands to form a mixed-metal coordination network.

Empirical correction of kinetic model for polymer thermal reaction process based on first order reaction kinetics

Based on the theory of first-order reaction kinetics,a thermal reaction kinetic model in integral form has been derive.To make the model more applicable,the effects of time and the conversion degree on the reaction rate parameters were considered.Two types of undetermined functions were used to compensate for the intrinsic variation of the reaction rate,and two types of correction methods are provided.The model was explained and verified using published experimental data of different polymer thermal reaction systems,and its effectiveness and wide adaptability were confirmed.For the given kinetic model,only one parameter needs to be determined.The proposed empirical model is expected to be used in the numerical simulation of polymer thermal reaction process.

Syntheses,Crystal Structures and Thermal Stabilities of Two New Mixed Ligated Coordination Polymers with Rigid Dicarboxylate and Flexile N-donor Ligands

Two new coordination polymers,[Co（BIPA）（bpp）]（1） and [Zn（BIPA）（bpp）（H2O）]（2）（H2BIPA = 5-bromoisophthalic acid,bpp = 1,3-di（4-pyridyl）propane） have been synthesized via hydrothermal reactions.The two compounds were characterized by elemental analysis,IR spectra,TG analysis and single-crystal X-ray determination.Compound 1 crystallizes in triclinic,space group P1 with a = 9.0316（13）,b = 10.1179（14）,c = 11.8884（17） ,α = 68.022（2）,β = 84.749（2）,γ = 77.791（2）°,V = 984.5（2） 3,Z = 2,C21H17BrN2O4Co,Mr = 500.21,Dc = 1.687 g.cm-3,μ = 2.932 mm-1,S = 0.981,F（000） = 502,R = 0.0440 and wR = 0.1357 for 3773 observed reflections with I 2σ（I）.Compound 2 crystallizes in the monoclinic system,space group P21/c with a = 7.8466（10）,b = 27.483（4）,c = 9.6583（13） ,β = 96.663（3）°,V = 2068.8（5） 3,Z = 4,C21H19BrN2O5Zn,Mr = 524.66,Dc = 1.685 g.cm-3,μ = 3.155 mm-1,S = 0.969,F（000） = 1056,R = 0.0441 and wR = 0.0517 for 4058 observed reflections with I 2σ（I）.The two compounds are constructed from the BIPA2-and bpp ligands but they exhibit different kinds of one-dimensional chain structures.In 1,the chains are composed of the Co（Ⅱ） ions and BIPA2-ligands,and the chains are further extended into a 2D framework structure by π...π interactions of the benzene rings from the BIPA2-ligands between the adjacent chains.In 2,the chains are made up of Zn（Ⅱ） ions and BIPA2-ligands through another fashion,and the chains are further linked via hydrogen bonding interactions to yield a two-dimensional supramolecular layer structure.Furthermore,the bpp ligand features two kinds of different coordination modes in the two compounds.

A New Co(Ⅱ) Coordination Polymer Based on a Flexible 1,4-Cyclohexanedicarboxylic Acid: Synthesis, Structure and Thermal Behavior

A new Co(Ⅱ) coordination polymer, [Co(1,4-chdc)(L)(H2O)]n(1), was synthesized under hydrothermal condition(1,4-H2chdc = 1,4-cyclohexanedicarboxylic acid, L = 2-(4-fluoro-phenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Its crystal structure was determined by single-crystal X-ray diffraction. 1 crystallizes in triclinic, space group P1 with a = 8.790(5), b = 10.486(5), c = 13.305(5)A, α = 87.391(5), β = 82.925(5), γ = 81.841(5)°, V = 1204.2(10)A^3, Z = 2, C27H23FN4O5Co, Mr = 561.42, Dc = 1.548 g/cm^3, F(000) = 578, μ(Mo Ka) = 0.769 mm^-1, R = 0.0415 and wR = 0.1043. In 1, each 1,4-chdc anion bridges two neighboring Co(Ⅱ) atoms to give a chain structure. The L ligands are attached on one side of the chain through chelating the Co(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a double-chain structure. The double-chain structures are linked into a supramolecular layer structure through N–H…O hydrogen-bonding interactions between the adjacent double-chain structures. Moreover, the thermal behavior of 1 was also studied.

Hydrothermal Synthesis,Crystal Structure and Properties of a 1D Chain Copper(Ⅱ) Polymer with 3-(2-Pyridiyl)-1H-1,2,4-triazole(Hpt)

A new 1D copper（Ⅱ） polymer [Cu（Hpt）（3,5-DMBA）]n has been hydrothermally synthesized with copper acetate,3-（pyridin-2-yl）-1,2,4-triazole（Hpt） and 3,5-dimethylbenzoic acid（3,5-DMBA）. It crystallizes in triclinic space group P1,with a = 8.1974（6）,b = 8.3280（6）,c = 12.5021（9） ？,α = 84.3320（10）,β = 71.8870（10）,γ= 65.4560（10）o,V = 737.44（9） ？~3,Dc = 1.612 g/cm3,Z = 2,F（000） = 366,GOOF = 1.035,R = 0.0298 and w R = 0.0855. The crystal structure is a one-dimensional（1-D） chain in which the Cu（Ⅱ） is five-coordinated with square pyramidal geometry. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ12-η：η0-3,5-dimethylbenzoic acid anions and two 3-（pyridin-2-yl）-1,2,4-triazole molecules. The coordination environment of Cu（Ⅱ） ion is CuO＋2N_3. The luminescence and thermal properties of the complex were investigated.

Synthesis,Crystal Structure and Thermal Behavior of a New 2D Barium(Ⅱ) Coordination Polymer with 1H-benzimi-dazole-5,6-dicarboxylate as the Single Ligand

The self-assembly of 1H-benzimidazole-5,6-dicarboxylic acid with barium chloride under hydrothermal conditions afforded a new 2D coordination polymer,[Ba2（L）（HL）Cl]n（1,L = 1H-benzimidazole-5,6-dicarboxylate）,which was characterized by elemental analysis,infrared spectroscopy,thermogravimetric analysis,and single-crystal X-ray diffraction.Compound 1 is of monoclinic system,space group P21/c with a = 10.0145（6）,b=25.6854（15）,c=7.3116（4） ？,β = 99.4980（10）°,V = 1854.95（19）3,C18H9Ba2ClN4O8,Z = 4,Mr=719.42,Dc = 2.576 g/cm3,μ（MoKα） = 4.427 mm-1,F（000） = 1352,the final R = 0.0202 and wR=0.0465 for 3051 observed reflections with I 2σ（I）.It exhibits an interesting two-dimensional network structure and high thermal stability（up to 420 ℃）.

Highly Thermally Conductive Polymer/Graphene Composites with Rapid Room‑Temperature Self‑Healing Capacity

Composites that can rapidly self-healing their structure and function at room temperature have broad application prospects.However,in view of the complexity of composite structure and composition,its self-heal is facing challenges.In this article,supramolecular effect is proposed to repair the multistage structure,mechanical and thermal properties of composite materials.A stiff and tough supramolecular frameworks of 2-[[(butylamino)carbonyl]oxy]ethyl ester(PBA)–polydimethylsiloxane(PDMS)were established using a chain extender with double amide bonds in a side chain to extend prepolymers through copolymerization.Then,by introducing the copolymer into a folded graphene film(FGf),a highly thermally conductive composite of PBA–PDMS/FGf with self-healing capacity was fabricated.The ratio of crosslinking and hydrogen bonding was optimized to ensure that PBA–PDMS could completely self-heal at room temperature in 10 min.Additionally,PBA–PDMS/FGf exhibits a high tensile strength of 2.23±0.15 MPa at break and high thermal conductivity of 13±0.2 W m^(−1)K^(−1);of which the self-healing efficiencies were 100%and 98.65%at room temperature for tensile strength and thermal conductivity,respectively.The excellent self-healing performance comes from the efficient supramolecular interaction between polymer molecules,as well as polymer molecule and graphene.This kind of thermal conductive self-healing composite has important application prospects in the heat dissipation field of next generation electronic devices in the future.

Hydrothermal Synthesis, Structure and Thermal Stability of a Copper Coordination Polymer Bridged by Pimelic Acid

A novel one-dimensional chain copper（Ⅱ） coordination polymer { [Cu（2,2′-bipy）- （HPDA）]（HPDA）（H2O）}n has been hydrothermally synthesized using pimelic acid, 2,2′-bipyridine and copper perchlorate in the mixture of water and methanol. The crystal structure was determined as a monoclinic system, space group P21/c, with a= 1.01139（14）, b = 2.6898（4）, c = 1.02105（14）, β = 109.651（2）°, V = 2.6159（6） nm^3, Dc = 1.412 g/cm^3, Z = 2, F（000） = 1164, GOOF = 1.044, R = 0.0570 and wR = 0.1448. The copper ion is coordinated with two nitrogen atoms of one 2,2′- bipyridine molecule and three oxygen atoms from two heptane diacid molecules, forming a distorted square-pyramidal geometry. The result of TG analysis shows that the title complex is stable under 200.0 ℃.

Crystal Structure and Thermal Stability Properties of a New 1D Chain Cu(Ⅱ)Coordination Polymer with2,3-Pyridinedicarboxylic Acid as the Ligand

A new 1D chain copper coordination polymer [CuE（H2L）2（C10HsN2）（HEO）2]n＇3n（H20） with 2,3-pyridinedi carboxylic acid （H2L） and 2,2＇-bipyridine （2,2＇-bipy） as ligands has been synthesized in the mixed ethanol and water solvents. Crystal data for this complex are as follows： monoclinic, space group P2Jc, a = 7.7713（7）, b = 27.478（3）, c = 13.2621（13）/1,, fl = 100.6940（10）, V= 2782.8（5） A3, Dc = 1.722 g/cm3, Z = 4, p = 1.61 mm-1, F（000） = 1472, the final R = 0.0363 and wR = 0.0933. In the crystal structure, the whole molecule consists of two cooper ions, two H2L, one 2,2＂-bipy molecule and six water molecules. Each central copper ion is coordinated with three oxygen atoms from two H2L and one water molecule, two nitrogen atoms from one 2,2＇-bipy molecule and two H2L, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.

Synthesis, Crystal Structure and Thermal Stability of a New Cadmium(II) Polymer Based on 1H-pyrazole-3-carboxylic Acid Ligand

A novel Cd（Ⅱ） coordination polymer, [CdCI（Hpc）H2O]n （1, H2pc = 1H-pyrazole-3- carboxylic acid）, was synthesized by the reaction of CdCl2·2.5H2O with H2pc, and structurally characterized by IR spectrum, UV-Vis spectrum, elemental analysis, single-crystal X-ray diffraction, as well as thermal analysis. Compound 1 crystallizes in monoclinic, P21/n space group with α = 7.0304（3）, b = 10.3047（3）, c = 10.6446（4） A, β= 107.174（4）°, F = 736.78（5） A^3, Z = 4, C4HsCdClN2O3, Mr = 276.95, Dc = 2.497 g/cm%3, F（000） = 528.0,μ= 3.281 mm^-1, R = 0.0169 and wR = 0.0387. The central metals adopt distorted octahedral geometry. Carboxyl groups of the ligand connect Cd（Ⅱ） into a one-dimensional chain, which further constructs a two-dimensional network by halogen bridging. Such two-dimensional structures are finally connected into a three-dimensional supramolecular architecture due to the hydrogen bonds and intermolecular π…π interactions. In addition, complex 1 has high thermal stability.

Synthesis,Crystal Structure and Thermal Stability Properties of a Binuclear Copper(Ⅱ) Coordination Polymer {[Cu_2(4,4'-bipy)_2(o-ABA)_4(H_2O)_2][(H_2O)_2]}_n

One-dimensional chain copper（Ⅱ） coordination polymer has been synthesized and characterized in the solvent mixture of water and alcohol with o-acetamidobenzoic acid,4,4＇-bipyridine and copper perchlorate.It is of tetragonal,space group P41212 with a=1.57756（10）,b= 1.57756（10）,c=2.1438（3）nm,V=5.3352（8） nm^3,Dc=1.524 g/cm^3,Z=4,F（000）=2536,R= 0.0479 and wR=0.0979.The crystal structure shows two coordination modes.The copper（1） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule and two oxygen atoms from two o-acetamidobenzoic acid molecules,forming a distorted tetrahedral coordination geometry; the copper（2） is coordinated with two nitrogen atoms of one 4,4＇-bipyridine molecule,four oxygen atoms from two o-acetamidobenzoic acid molecules and two water molecules,generating a distorted octahedral coordination geometry.The result of TG analysis shows that the title complex is stable below 180.0 ℃.

Experimental Measurements of the Sensitivity of Fiber-optic Bragg Grating Sensors with a Soft Polymeric Coating under Mechanical Loading,Thermal and Magnetic under Cryogenic Conditions

The strain and temperature sensing performance of fiber-optic Bragg gratings （FBGs） with soft polymeric coating, which can be used to sense internal strain in superconducting coils, are evaluated under variable cryogenic field and magnetic field. The response to a temperature and strain change of coated-soft polymeric FBGs is tested by comparing with those of coated-metal FBGs. The results indicate that the coated-soft polymeric FBGs can freely detect temperature and thermal strain, their At variable magnetic field, the tested results indicate accuracy and repeatability are also discussed in detail. that the cross-coupling effects of FBGs with different matrixes are not negligible to measure electromagnetic strain during fast excitation. The present results are expected to be able to provide basis measurements on the strain of pulsed superconducting magnet/cable （cable- around-conduit conductors, cable-in-conduit conductors）, independently or utilized together with other strain measurement methods.